For work mornings, am lazy and uncreative, so usually a ponytail.
I also work in a lab, and I'd rather not have to worry about dipping my hair in chemicals, so ponytails are easiest.
On the weekends, sometimes I'll just wash it and let it down to do whatever it wants. I am more wavy than curly after the past few years, and I don't have any products that I really like for it, so some days this results in good hair that I leave down, some days this results in major frizz that gets tossed into a ponytail. I have also discovered that, as my hair has lost curl, I can blow it straight much easier than I used to, so I do that sometimes as well.